In the display technology field, flat panel display devices such as liquid crystal display (LCD) and organic light emitting diode (OLED) display devices have gradually replaced cathode ray tube (CRT) display devices.
The liquid crystal display device has many advantages such as a thin body, power saving, and no radiation, and has been widely applied. Most of the liquid crystal display devices in the current market are backlight type liquid crystal display devices, which include a liquid crystal display panel and a backlight module. Generally, the liquid crystal display panel is formed by a color filter (CF) substrate, a thin-film transistor (TFT) array substrate, a liquid crystal (LC) clamped between the color filter substrate and the thin-film transistor array substrate, and a sealant.
The operation principle of the liquid crystal display panel is to place liquid crystal molecules in two parallel glass substrates. There are many vertical and horizontal fine wires in the middle of the two glass substrates, and the liquid crystal molecules are controlled to change directions by applying a voltage or not, and refracting the light of the backlight module to generate an image.
With the continuous development of science and technology, people's living standards have been continuously improved, and consumers have become increasingly demanding for the quality of liquid crystal display devices, which has led to the development of resolution of liquid crystal display devices in an increasingly higher direction. However, since the collection of digital image signals lags behind the development of liquid crystal display devices, the problem of displaying low-resolution image signals on a high-resolution liquid crystal display device is often encountered. This requires processing the low-resolution images and converting the low-resolution images to high resolution image signals for normally displaying on a high-resolution liquid crystal display device.
However, a high-resolution image signal converted from a low-resolution image signal has a problem of blurring at the edges of the image. Because after the resolution is increased, the grayscale level is gradually changed at the edges for the pixel at the edge of the image, and the gradient value of the pixel at the transient region is decreased, which serious affect the display-quality of the image.